Conventionally, an electric power has been applied by a signal source to a load in network analyzers and spectrum analyzers (refer to patent document 1 (Japanese Laid-Open Patent Publication (Kokai) No. H11-38054), for example). The signal source and the load are connected via a transmission line. On this occasion, there exist the output impedance of the signal source, the impedance of the load, and the characteristic impedance of the transmission line. If the output impedance of the signal source and the impedance of the load match the characteristic impedance of the transmission line, a correct electric power can be applied to the load.
However, the output impedance of the signal source and the impedance of the load are often different from the characteristic impedance of the transmission line. In this case, a correct electric power cannot be applied to the load. Moreover, it is difficult to manufacture a signal source whose output impedance matches the characteristic impedance of the transmission line. Consequently, a correct electric power often cannot be applied to the load.
The purpose of the present invention is to apply a correct electric power to the load upon the output impedance of the signal source and the impedance of the load being different from the characteristic impedance of the transmission line.